The problem of bed sores and blisters experienced by people confined to bed for extended lengths of time is well documented. The primary cause of bed sores is the immobility of a bed-ridden patient which causes an interruption in the flow of blood to capillaries and areas of the skin adjacent bone protuberances (shoulder blades and heels, for instance). The interruption of blood flow to the capillaries causes skin cells to die which results in a breakdown of skin tissue and the development of bed sores. Further, any build-up of moisture, due to perspiration for example, exacerbates the bed-sore problem.
Ventilating air mattresses have been developed which accept pressurized air through an aperture and have a plurality of pores through their top surfaces enabling a controlled flow of air to escape therethrough. These mattresses are effective in distributing the support of a patient over a greater area of the patient's body, thereby relieving some pressure in the areas of bone protuberances. The controlled flow of air also assists in drying perspiration.
However, the prior art ventilating air mattresses are expensive, inefficient and cumbersome. As illustrated in U.S. Pat. No. 4,768,249 issued to Goodwin and Great Britain Patent No. 1,545,806 issued to Hopkins, the prior art ventilating air mattresses are elaborately constructed. These ventilating air mattresses require a specially tailored bed frame and each inflatable cell must meet precise material tolerances. This elaborate construction significantly increases the unit cost of each bed.
While the prior art mattresses add significant expense to the unit cost of each bed, the mattresses are inefficiently designed. Much of the expense simply does not assist in reducing bed sores. For instance, the prior art mattresses vent air along the entire longitudinal top surface of the mattress resulting in two significant, and costly, inefficiencies. First, as explained above, bed sores are most frequently localized near skin areas adjacent bone proturbances. However, the prior art ventilating air mattresses do not address this localized phenomenon. In the prior art, each body region (head, middle abdomen, and lower legs) of a given patient is supported by the elaborate and expensive mattress design whether or not each body region is susceptible to bed sores. Thus, the elaborate and expensive mattress construction is unnecessarily employed to support body regions unlikely to experience bed sores. Second, the prior art mattresses support the patient's entire weight over the ventilating air surface of the mattress thereby requiring a sizable air pump (often specifically design for this purpose) to maintain appropriate inflation throughout the entire mattress. The additional expense of the oversized air pump and increased operating expense required to continually vent air to non-bed-sore susceptible body regions is wasted.
Further, while ventilating air mattresses have been developed employing multiple separate inflatable cells, those prior art mattresses are designed, manufactured and assembled for permanence. Each cell (from head to toe) is a ventilating air cell, and elaborate mechanisms for attaching the mattress cells to a specialized bed frame, which was often tailored specifically for these ventilating mattresses, is required along with sophisticated pump assemblies. This design criteria creates a sturdy and permanent mattress at the expense of mobility, adaptability and ease of assembly. Therefore, if elevation of the leg region or head region of a given patient (as may be required for a patient's injury or illness) redistributes the patient's body weight relative to the mattress and alters the body regions susceptible to bed sores, the inefficient design of the prior art ventilating air mattress again fails to allow the mattress assembly to adapt to the patient's changing needs. Each body region is continually supported by an expensive ventilating air mattress piece with no concern that repositioning of the body may render specific body regions non-susceptible to bed sores.
Moreover, because the prior art ventilating air mattresses are designed for permanence, if a mattress piece fails or becomes contaminated, it is cumbersome and time-consuming to access an individual piece and quite difficult to replace or reposition individual pieces. As a result, hospitals and nursing homes are required to inventory entire spare beds, and entire spare ventilating air mattresses, to be used as substitutes until a failed/contaminated piece (section) of the original ventilating air mattress is repaired or replaced. This inventory requirement further increases the expense associated with the prior art mattresses.
The present invention overcomes the foregoing problems by providing a modular air mattress having three separate pieces, one to support a head region, one to support a middle abdomen region, and one to support a lower leg region of a patient. The mattress pieces include a low air loss ventilating mattress piece (hereinafter "ventilating air mattress") and two conventional, non-ventilating mattress pieces, which are interchangeable to accommodate a patient's needs. For instance, the considerably more expensive ventilating air mattress piece is only positioned beneath the region of a patient's body deemed susceptible to bed sores, while the less expensive, conventional mattress pieces are positioned beneath the remaining body regions. Each piece has means for releasably coupling to each of the other pieces so that the ventilating air mattress piece and conventional mattress pieces may be conveniently positioned, and securely coupled, in any longitudinal series.
The releasable coupling means facilitates convenient rearrangement, or replacement, of mattress pieces in the event a piece fails or becomes contaminated, or to accommodate a patient's changing needs. The nurse or medical technician begins by selecting a mattress piece to be replaced or rearranged, decoupling the selected piece from its adjacent piece(s), removing the selected piece from the mattress, and replacing/rearranging the piece. The mattress piece is then coupled to its adjacent piece(s).
This invention is a significant improvement over the prior art in that the elaborate and expensive ventilating air mattress pieces are efficiently utilized by selectively positioning the ventilating air mattress pieces to only support bed-sore susceptible body regions. Using conventional mattress pieces to support the non-bed-sore susceptible body regions reduces the unit cost of each bed. Moreover, because ventilating air mattress pieces only support a fraction of a patient's body weight (the conventional mattress pieces support the remainder), a smaller air pump may be used while still maintaining appropriate inflation, thereby further reducing the unit bed cost and correspondingly minimizing the air pump operating expense of this mattress.
Furthermore, the releasable coupling means of this invention allows the mattress pieces to be quickly and conveniently rearranged to accommodate a patient's changing needs or to accommodate a new patient. The releasable coupling means is especially helpful when one mattress piece fails or becomes contaminated. Rather than replacing the entire bed, or taking the bed out of service to repair the damaged mattress piece, when one mattress piece of this invention fails or is contaminated, the piece is very easily replaced by a nurse or medical technician, thereby reducing maintenance costs, freeing medical and maintenance personnel time, and minimizing the cost associated with inventorying entire spare beds and entire spare mattresses.